Synthesis, characterization, molecular docking studies and in vitro screening of new metal complexes with Schiff base as antimicrobial and antiproliferative agents

Abstract

A series of Cu(II), Co(II), Pd(II), Pt(II), Zn(II), Cd(II) and Fe(III) complexes were designed and synthesized using Schiff base 1‐phenyl‐2,3‐dimethyl‐4‐(N‐3‐formyl‐6‐methylchromone)‐3‐pyrazolin‐5‐one (HL). The new metal complexes were investigated using various physicochemical techniques including elemental and thermal analyses, molar electric conductivity and magnetic susceptibility measurements, as well as spectroscopic methods. Also, the crystal structures of ligand HL and the Pd(II) complex were determined using single‐crystal X‐ray diffraction analysis. For all compounds, the antimicrobial activity was studied against a series of standard strains: Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Escherichia coli, Acinetobacter baumannii, Candida albicans, Candida krusei and Cryptococcus neoformans. The in vitro antiproliferative activity of the ligand and complexes was evaluated against ten cancer cell lines: MSC, A375, B16 4A5, HT‐29, MCF‐7, HEp‐2, BxPC‐3, RD, MDCK and L20B. At 10 μM concentration a significant cytotoxic effect of the Co(II), Pd(II) and Cd(II) complexes was observed against B16 4A5 murine melanoma cells. The Zn(II) complex is active against HEp‐2, RD and MDCK cancer cell lines, where IC50 values vary between 1.0 and 77.6 and for BxPC‐3 the activity index versus doxorubicin is 3.7 times higher.

Fragmentation Study, Dual Anti-Bactericidal and Anti-Viral Effects and Molecular Docking of Cobalt(III) Complexes

“…On the other hand, the best free binding energy between CHD and bacteria was found for E. faecalis (−11.24 kcal/mol), followed by S. sanguinis (−9.49 kcal/mol), and the highest value was found for S. mitis (−3.03 kcal/mol). Energy derived from the cobalt complex interaction with the L. paracasei structure was lower compared to the energy derived from CHD interaction with the same bacteria structure, suggesting that the complex couple is more stable, a fact observed for other metal complexes in the literature [41,42]. This observation is also in accordance with the antibacterial assay results which show a higher biological activity for [Co(atc-Ph) 2 ] + (MIC/MBC = 0.39/0.39 µg/mL) than for CHD (MIC/MBC = 0.92/0.92 µg/mL).…”

“…It is evident from the results obtained that both the [Co(atc-Ph) 2 ] + complex and CHD can successfully bind to one or more amino acids of all bacteria. The results of ∆G obtained were highly exothermic, which reveals good orientation and proximity, demonstrating the increment of the binding affinity [41]. The free binding energy between the [Co(atc-Ph) 2 ] + complex and bacteria was found to be −9.55 kcal/mol for L. paracasei, followed by −8.66 kcal/mol found for S. sanguinis.…”

Synthesis, characterization, crystal structure and toxicity evaluation of Co (II), Cu (II), Mn (II), Ni (II), Pd (II) and Pt (II) complexes with Schiff base derived from 2‐chloro‐5‐(trifluoromethyl)aniline

“…The magnetic moment value (5.10 MB) and the brown color of this complex support octahedral geometry. [ 43,44 ]…”

Chromium Coordination Compounds with Antimicrobial Activity: Synthetic Routes, Structural Characteristics, and Antibacterial Activity

“…The abundance of electronic spectral bands within this complex also provided proof of the complex's trinuclearity. [19,70]. Based on these data, octahedral geometry was proposed for C5.…”